A new visitor to the institute for Advanced Study in Princeton, N.J., might at first think it was abandoned. A cluster of buildings that sits on the edge of a weedy field behind a wooden sign whose paint is chipping, the institute is not a university or a typical research center but a place where a couple hundred geniuses--Albert Einstein was an early faculty member--can go, for varying lengths of time, to indulge their curiosity. About a 20-minute walk from Princeton University (the two are not affiliated), it feels nothing like it. There are no undergraduates walking on the paths, no...